One of the easiest ways to launch a Python script is via ``Drag and
Drop''. This is just like launching a text file in the Finder by
``dragging'' it over your word processor's icon and ``dropping'' it
there. Make sure that you use an icon referring to the
PythonInterpreter, not the IDE or Idle
icons which have different behaviour which is described below.

Some things that might have gone wrong:

A window flashes after dropping the script onto the
PythonInterpreter, but then disappears. Most likely this is a
configuration issue; your PythonInterpreter is setup to exit
immediately upon completion, but your script assumes that if it prints
something that text will stick around for a while. To fix this, see
section 1.7.3.

After dropping the script onto the PythonInterpreter, a
window appeared which said: ``File contains \r characters
(incorrect line endings?)''. That script probably originated on a
Unix or Windows machine. You will need to change the line endings
to the standard Mac usage. One way to do this is to open the file in
BBedit
(http://www.barebones.com/products/bbedit_lite.html) which can
easily change the line endings between Mac, DOS, and Unix styles.

When you waved the script icon over the PythonInterpreter,
the PythonInterpreter icon did not hilight. Most likely the
Creator code and document type is unset (or set incorrectly) - this
often happens when a file originates on a non-Mac computer. See
section 1.3.2 for more details.